Loaded solvent streams can be obtained from processes for removing contaminants such as acidic compounds from a gas stream by washing the gas stream with fresh solvent. The use of solvents for removing contaminants such as acidic gasses is well known, see for instance the books A. L. Kohl and F. C. Riesenfeld, 1974, Gas Purification, 2nd edition, Gulf Publishing Co. Houston and R. N. Maddox, 1974, Gas and Liquid Sweetening, Campbell Petroleum Series.
Preferably, a regenerable solvent is used in a continuous process.
Generally, loaded solvent streams are treated by removing the contaminant and regenerating the solvent. The removal of the contaminant from the loaded solvent stream can be effected for example by contacting the loaded solvent stream with a suitable stripping agent and removing the contaminant from the loaded stripping agent. In the case where the concentration of contaminant in the loaded solvent varies with time, the concentration of the contaminant in the loaded stripping agent will also vary in time. The contaminant removal from a loaded stripping agent that has a time-varying concentration of contaminant can cause problems, especially when the conditions such as temperature, pressure, size of catalyst bed etc. required to remove such a contaminant depend to a large extent on the concentration of the contaminant.
It is therefore desirable to provide a treating process enabling the further processing of loaded solvents with a time-varying concentration of contaminant.